Oral Presentation Australian & New Zealand Obesity Society 2016 Annual Scientific Meeting

Effects of exercise on appetite and gut hormones: implications for weight management. (#79)

Shelley E Keating 1 2 , Ahmad Alzahrani 3 4 , Jenna Kirchner 2 , Ian D Caterson 3 , Neil A King 5 , Nathan A Johnson 1 3 , Radhika V Seimon 3 , Amanda Sainsbury 3
  1. Faculty of Health Sciences, The University of Sydney, Sydney, NSW, Australia
  2. School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, QLD, Australia
  3. The Boden Institute of Obesity, Nutrition, Exercise & Eating Disorders, Sydney Medical School, Charles Perkins Centre, The University of Sydney, Sydney, NSW, Australia
  4. Faculty of Medicine, The University of Jeddah, Jeddah, Saudi Arabia
  5. Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia

Background: Regular exercise is essential for long-term weight maintenance; however, the role of exercise in weight loss is sometimes questioned due to the potential compensatory increases in hunger and food intake, associated with changes in appetite hormones. We examined the effects of exercise training on appetite and gut hormones, in addition to energy intake, subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) in adults with overweight/obesity.

Methods: Twenty-three inactive adults with overweight/obesity (BMI 33.3 ± 5.5 kg/m2) aged 47 ± 9 years were randomised to 8-weeks of aerobic (n=17, 30-60 minutes per session at 50-70% of VO2peak, 3-4 days/week) or resistance exercise training (n=5, 8-10 exercises per session, 8-12 repetitions, 2-3 sets per exercise at 80-85% of 1-repetition maximum, 3 days/week). Intervention group data (aerobic and resistance exercise training) were combined for data analyses. Participants were instructed not to alter their diet. Before and after the intervention, fasting subjective appetite sensations (using visual analogue scale) and plasma for gut hormone assays were collected after an overnight fast. Energy intake was recorded using 3-day food diaries, and VAT and SAT were measured via magnetic resonance imaging. Changes from baseline were analysed using paired t-tests.

Results: Eight-weeks of both exercise training interventions induced significant reductions in VAT (-159 ± 195 cm3, p<0.001) and SAT (-331 ± 756 cm3, p=0.003), with no significant changes in weight (-0.9 ± 2.2 kg, p=0.07), subjective appetite sensations, plasma ghrelin, PYY or energy intake (p>0.05 for all).

Conclusions: In the absence of explicit dietary restrictions in adults with overweight/obesity, neither type of exercise training, which effectively reduces body fat without weight loss, affects fasting subjective sensations of appetite, or fasting plasma levels of ghrelin or PYY. Exercise-induced changes in body composition appear not to be influenced by changes in gut hormones.

Supported by Diabetes Australia Research Trust